An increasing number of biomedical journals are being made available for online searching via full-text, that is, the complete text of each article is sorted and any article may be retrieved by a single word or combinations of words contained therein. This represents a dramatic increase in points of access to information in these journals. In some cases, however, full-text availability may present a surfeit of access points and hinder the identification of the most relevant documents. Controlled index terms, on the other hand, represent judgments regarding the important concepts in documents, and judgments are subject to human error. This project is designed to test the relative efficacy of index terms and full-text for the retrieval of documents in those MEDLINE journals for which full-text searching is also available. Information requests will be solicited from the Departments of Medicine, Surgery, Family and Community Medicine, and Child Health at the University of Missouri-Columbia Health Sciences Center. Trained and experienced searchers will search both the MEDLINE database and the corresponding full-text databases for relevant citations. All citations retrieved will be evaluated for relevance by the requesters. Results will be tabulated and analyzed to determine which of the retrieval methods is more effective in identifying relevant bibliographic citations, why full- text systems miss some relevant documents, and whether one method is more effective than the other for certain kinds of questions. In addition, data will be analyzed to determine how often relevant items in full-text systems could have been identified with title and abstract words alone.